It's hot, what should dogs do if they are always listless?

At present, it is normal for dogs to lose appetite and not love activities. As long as other indicators are normal, such as wet nose, normal drinking water and normal defecation, it is ok. Mine is the same, it doesn't move at all, but it deliberately takes it to swim far away, so happy that it withers as soon as it returns to the door. It's too hot, normal.